Delivery system for functional compounds

ABSTRACT

A delivery system for various functional compounds is disclosed. The delivery system incorporates a composition containing alumina. Various functional materials containing particular moieties may be adsorbed onto the alumina and used as desired. The functional compounds can be, for instance, pharmaceuticals, xenobiotics, anti-microbial agents, anti-viral agents, UV absorbers, odor control agents, fragrances, and the like. In one particular embodiment, for instance, certain dyes can be adsorbed onto the alumina surfaces. Once the dye is adsorbed onto the alumina surface, the resulting particles can be combined with a liquid vehicle for use in any suitable printing process.

BACKGROUND OF THE INVENTION

[0001] A delivery system generally refers to a system that aids orotherwise facilitates the delivery of a functional material to a desiredlocation. The functional material can be any material that acts upon asubstrate or otherwise provides a benefit once delivered to the desiredlocation. Examples of functional materials that may benefit from the useof a delivery system include pharmaceuticals that are intended to beingested or subcutaneously injected into a patient, fragrances, vitaminsand nutrients, and various other and numerous additives.

[0002] In one particular application, for instance, the functionalmaterial can be a dye that is intended to be printed or otherwiseapplied to a substrate. In the past, various delivery systems for dyeshave been proposed that are intended to facilitate application of thedye to a substrate, such as a textile material. The delivery systems,for instance, are intended to affix the dye to a substrate, prevent thedye from fading when exposed to sunlight, to prevent the dye fromdegrading when exposed to the environment, to facilitate application ofthe dye to the substrate, or, for example, to render the dye morestable.

[0003] Even in view of recent advances in the art, further improvementsin delivery systems for functional materials are still needed. Forexample, a need currently exists for a delivery system that can bind tovarious functional materials that does not incorporate relativelyexpensive chemical formulations or that does not require any complexprocess steps for incorporating a functional material into the deliverysystem. With respect to dyes, a need also exists in the art for adelivery system for a dye that is capable of affixing the dye tonegatively charged surfaces. For example, a need currently exists for adelivery system for dyes that is capable of affixing the dyes to textilematerials containing natural or synthetic polymeric fibers that have anegative surface charge.

SUMMARY OF THE INVENTION

[0004] The present invention is generally directed to a delivery systemfor various functional materials. The functional materials can be, forinstance, colorants, UV absorbers, pharmaceuticals, odor control agents,fragrances, anti-microbial agents, anti-viral agents, antibiotics,xenobiotics, nutriceutical agents, and the like. In accordance with thepresent invention, the functional materials are adsorbed onto aluminathat is contained in a particle. The resulting particle can then be usedas is or can be combined with a vehicle, such as a liquid vehicle, todeliver the functional material to a desired location. For example, whenthe functional material is a colorant, the particles of the presentinvention can be incorporated into a liquid vehicle and applied to asubstrate using any conventional printing means.

[0005] Thus, in one embodiment, the present invention is directed to aparticle containing alumina. At least a portion of the alumina containedwithin the particle is present on a surface of the particle. Afunctional compound is bonded to the alumina on the surface of theparticle. The functional compound prior to bonding with the aluminacontains a moiety comprising:

[0006] a tautomer thereof, or a functional equivalent thereof andwherein R and R′ comprise independently hydrogen, an alkyl group, or anaryl group.

[0007] The above moieties can be present as is on a functional compound.Alternatively, however, each of the above moieties can include further Rgroups attached to the carbon chain shown above. In general, any such Rgroup can appear in association with the above moieties as long as the Rgroup does not interfere with the bonding of the moiety to an alumina.

[0008] The above moieties have been found to form a bond with alumina inconstructing the compositions of the present invention. Of particularsignificance, it was discovered that the functional compound, in someembodiments, can bond with alumina without significantly changing thepositive charge character of alumina. For example, under certainconditions, alumina may have a positive surface charge. It has beendiscovered that even after the functional material is bonded to thealumina, the resulting structure still maintains a positive charge.Thus, in one embodiment of the present invention, positively chargedparticles are formed. Due to their positive charge, the particles may besecurely affixed to the surface of a substrate that carries with it anegative charge through coulombic attraction.

[0009] In one particular embodiment of the present invention, novelrecording mediums, inks, and nanoparticles containing a colorantcompound may be formed. In accordance with the present invention, suchrecording mediums, when applied to substrates, exhibit improved waterand detergent resistance. For example, the delivery system of thepresent invention can improve the durability performance of therecording mediums especially to substrates having a negative charge. Forinstance, in one embodiment, a recording medium such as an ink-jet ink,can be produced according to the present invention that is substantiveto substrates containing synthetic polymeric fibers, such aspolypropylene fibers, polyethylene fibers, polyester fibers, and thelike.

[0010] Other features and aspects of the present invention are discussedin greater detail.

DETAILED DESCRIPTION

[0011] It is to be understood by one of ordinary skill in the art thatthe present discussion is a description of exemplary embodiments only,and is not intended as limiting the broader aspects of the presentinvention, which broader aspects are embodied in the exemplaryconstruction.

[0012] In general, the present invention is directed to a deliverysystem for functional compounds. Functional compounds can be anysuitable substance that can provide a benefit to a location oncedelivered. In accordance with the present invention, the delivery systemis generally directed to the construction of a particle containingalumina. The alumina contained within the particle provides a bondingsite on the surface of the particle for a functional compound.Specifically, the functional compound becomes adsorbed onto the surfaceof the alumina. Once the functional compound is bonded to the alumina,the resulting particle can then be used to deliver the functionalcompound to a particular location. The particles can be used as is, forinstance, or can be combined with a liquid vehicle which may facilitatedelivery of the particles depending upon the particular application.

[0013] Functional compounds that are well suited for use in the presentinvention include compounds that contain at least one of the followingmoieties:

[0014] a tautomer thereof, or a functional equivalent thereof andwherein R and R′ comprise independently hydrogen, an alkyl group, or anaryl group. As used herein, a functional equivalent to one of the abovemoieties refers to functional materials that include similar reactivegroups as shown above, but which are not positioned on a molecule asexactly shown above and yet will still bond with alumina in a similarmanner.

[0015] Referring to the moieties shown above, moiety (1) may beconsidered a carboxy-hydroxy moiety. Moiety (2) may be considered ahyrdoxy-hydroxy moiety, while moiety (3) may be considered acarboxy-carboxy moiety. Moieties (4) and (5), on the other hand, can beconsidered vinylalogous amide moieties. In moieties (4) and (5) above,the amine groups can be primary amines, secondary amines, or tertiaryamines. In general, any suitable functional compound containing one ofthe above moieties or a functional equivalent thereof may be used inaccordance with the present invention. Further, it should be understoodthat various additional R groups may be included with the above moietiesas long as the R groups do not interfere with the bond that is formedwith alumina.

[0016] The present inventors have discovered that the above moieties mayform a relatively strong bond to an alumina surface. The functionalcompounds may be bonded to the alumina surface in order to change theproperties of the resulting particle or to perform a particularfunction. Without wishing to be bound by theory, it is believed that theabove moieties form a bidentate ligand bonding system with aluminasurfaces. For instance, it is believed that alumina forms a covalentbond and a coordinate bond with the above moieties. Further, it isbelieved that a surface reaction occurs causing the functional compoundto remain on the surface of the particle and form a coating thereon. Thefunctional material can cover the entire resulting particle or can belocated at particular locations on the particle. Further, it should beunderstood that the particles of the present invention can contain morethan one functional compound.

[0017] Of particular advantage, in many embodiments, it has also beendiscovered that a functional compound can be bonded to alumina withoutsignificantly impacting on the positive surface charge of alumina, whichcan be measured as zeta potential. The term “zeta potential” is usedherein to mean without limitation a potential gradient that arisesacross an interface. This term especially refers to the potentialgradient that arises across the interface between the boundary layer incontact with the particle of the present invention and the diffuse layersurrounding the particle. Zeta potential measurements can be takenusing, for instance, a Zetapals instrument which are available from theBrookhaven Instrument Corporation of Holtsville, N.Y. For example, zetapotential measurements can be conducted by adding one to three drops ofa sample into a cuvet containing 1 mM KCl solution, using theinstrument's default functions preset for aqueous solutions.

[0018] Thus, once alumina is bonded to the functional material, theresulting molecule continues to maintain a relatively strong positivecharge. For instance, particles made according to the present inventioncan have a zeta potential of greater than 20 mV, particularly greaterthan 30 mV, and, in some embodiments, greater than 40 mV. By remainingpositively charged, the particles are well suited for being affixed tosubstrates that carry a negative surface charge through coulombicattraction. Depending upon the difference in charge between the particleof the present invention and the surface of a substrate, the bond insome applications can be relatively permanent and substantive.Consequently, the delivery system of the present invention can be usedto affix functional compounds to various substrates without the use ofchemical binders or other attachment structures.

[0019] Various different particles and compositions can be used in thepresent invention that contain alumina. For example, in one embodiment,the functional material is combined with an alumina sol. Many differenttypes of alumina sols are commercially available with varying particlesize. Of particular advantage, alumina sols can be prepared that carry arelatively strong positive surface charge or zeta potential. In thisembodiment, the particle that is reacted with the functional compoundcontains primarily and in some embodiments exclusively alumina.

[0020] In other embodiments, however, the particle reacted with thefunctional compound can contain various other ingredients. In general,the particle can contain any material that does not adversely interferewith ability of the functional material to bond to alumina. In thisregard, at least a portion of the alumina contained within the particleshould be present on the surface of the particle so that the alumina isavailable for adsorbing the functional compound.

[0021] In one particular embodiment of the present invention, theparticle can contain a core material coated with alumina. The aluminacan form a continuous coating over the particle or a discontinuouscoating. The core material can be, for instance, an inorganic oxide,such as silica. For example, in one embodiment, sols can be used thatcontain silica nanoparticles that have an alumina surface coating. Suchsols are currently commercially available, for instance, from NissanChemical America of Houston, Tex. The silica is coated with alumina toprovide stability to the sols over certain pH ranges. In fact, aluminacoated silica sols may have greater stability in some applications ofthe present invention in comparison to alumina sols.

[0022] As described above, any suitable functional compound containingone of the above moieties, a tautomer thereof, or a functionalequivalent thereof may be used in accordance with the present invention.Examples of functional compounds include pharmaceuticals, andxenobiotics. Xenobiotics is a general term used to describe any chemicalinteracting with an organism that does not occur in the normal metabolicpathways of that organism. Other functional compounds can include UVabsorbers, odor control agents, fragrances, therapeutic agents,nutriceutical agents, anti-viral agents, anti-microbial agents, and thelike. One example of a therapeutic agent that may be used in the presentinvention is hydrocortisone. Examples of nutriceutical agents includeascorbic acid and aspartame. In one particular embodiment, thefunctional compound may be tetracycline, which is a known antibacterialagent.

[0023] In still another embodiment of the present invention, thefunctional compound can be a colorant, such as dye. Particular examplesof dyes that may be used in accordance with the present invention arediscussed in greater detail below.

[0024] Once any of the above-mentioned functional compounds are bound toalumina, the alumina acts as a delivery vehicle for delivering thefunctional compound to a desired location. Once bound to the alumina,the functional compounds may be easier to handle, may be more stable, ormay have other improved properties depending upon the application.Further, the resulting alumina structure can be incorporated intovarious other mediums. For instance, the alumina structure can beincorporated into liquid vehicles, can be formed into capsules, can becombined with gels, pastes, other solid materials, and the like.

[0025] The particles formed according to the present inventioncontaining alumina and the functional compound can be present in variousforms, shapes, and sizes depending upon the desired result. Forinstance, the particles can be of any shape, for example, a sphere, acrystal, a rod, a disk, a tube, or a string of particles. The size ofthe particle can also vary dramatically. For instance, in oneembodiment, the particles can have an average dimension of less thanabout 1 mm, particularly less than about 500 microns, and moreparticularly less than about 100 microns. In other embodiments, however,even smaller sizes may be desired. For instance, the particles can havean average diameter of less than about 1,000 nm, and particularly lessthan about 500 nm. As used herein, the average dimension of a particlerefers to the average length, width, height, or diameter of a particle.

[0026] As described above, the particles of the present inventioninclude a surface layer that contains one or more functional compounds.The coating on the particle can be continuous or discontinuous. Theparticle itself is amorphous.

[0027] In one particular embodiment, the present invention is directedto a delivery system for dyes. In particular, it has been discoveredthat the use of alumina as described above provides various advantagesand benefits when attempting to apply a dye to a substrate. Forinstance, it has been discovered that the alumina delivery system canprovide a means to make permanent prints onto substrates havingnegatively charged surfaces, such as substrates containing thermoplasticpolymers as well as natural fibers. The ink becomes affixed to thesubstrate at relatively low cost and low complexity without the use ofchemical binders and without the use of a pre-treatment orpost-treatment process on the substrate.

[0028] For example, once a dye is adsorbed onto alumina in accordancewith the present invention, for many applications, the resultingparticle has a positive charge. Thus, the particle can be affixed tonegatively charged surfaces through coulombic attraction. Depending uponthe charge difference between the particles and the substrate, the dyemay exhibit permanent properties such as wash fastness by beingresilient to water and detergents. For example, generally wash fastnesscan be obtained if the charge difference between the substrate and theparticle is greater than about 42 mV.

[0029] In general, any dye containing a carbonyl-hydroxy moiety, ahydroxy-hydroxy moiety, a carbonyl-carbonyl moiety, a vinylalagous amidemoiety, a tautomer thereof, or a functional equivalent thereof asdescribed above may be used in the process of the present invention.Various examples of dyes that may be adsorbed onto alumina are asfollows. It should be understood, however, that the below list is notexhaustive and is not intended as limiting the invention.

Dyes Containing the Anthraquinone (5) Chromophore

[0030]

[0031] Numbers indicate the substitution positions of the anthraquinonestructure. This table indicates dye substituents that occur at positions1, 4, 5, or 8 on the anthraquinone structure. In other words, this tableshows the presence of groups that form alumina bonding moieties 1through 5. Substituent at Other groups position present Name 1 or 4 or 5or 8 include Cl Acid Black 48 NH2 SO3Na Cl Acid Blue 25 NH2 SO3Na ClAcid Blue 40 NH2 SO3Na Cl Acid Blue 41 NH2 SO3Na Cl Acid Blue 45 OH, NH2SO3Na Cl Acid Blue 129 NH2 SO3Na Cl Acid Green 25 NHAr SO3Na Cl AcidGreen 27 NHAr SO3Na Cl Acid Green 41 OH, NHAr SO3Na Cl Mordant Red 11 OH(Alizarin) Cl Mordant Black 13 OH, NHAr SO3Na (Alizarin Blue Black B)Alizarin Complexone OH (Aldrich 12,765-5) Cl Mordant Red 3 OH SO3Na(Alizarin Red S) Cl Natural Red 4 OH COOH (Carminic Acid) Cl DisperseBlue 1 NH2 Cl Disperse Blue 3 NH(alkyl) Cl Disperse Blue 14 NHCH3 EmodinOH (6-methyl-1,3,8-trihydroxy anthraquinone) Nuclear Fast Red OH, NH2SO3Na (Heliofast Rubine BBL) Cl Natural Red 16 OH (Purpurin) Cl NaturalRed 8 OH Quinalizarin OH Quinizarin OH Cl Reactive Blue 2 NH2, NHArSO3Na Solvent Green 3 NHAr

Dyes Containing Salicylate, or 3-hydroxy-2-naphthoic Acid Moieties

[0032] Dyes containing salicylate (6, R=OH), Salicamide (6, R=NH2, NHAr,NHAlk), or BON acid (3-hydroxy-2-naphthoic acid) (7, R=OH) or anitrogenous BON acid derivative (7, R=NH2, NHAr, NHAlk) moiety as shownbelow may also be used in accordance with the present invention. Thesedyes often fall into the Colour Index Mordant application class.

Substantive Colorant Group Chromophore Aluminon (tri ammonium salt)Salicylate TPM (Aurintricarboxylic acid) (Cl Mordant Violet 39 is thetrisodium salt) Cl Mordant Blue 29 Salicylate TPM Cl Mordant Blue 3Salicylate TPM (Chromoxane Cyanine R) BON acid Azo Calconcarboxylic acid3-hydroxy-4-(2-hydroxy-4-sulfo-1-naphthylazo) -2-naphthalenecarboxylicacid CI Mordant Orange 1 Salicylate Azo (Alizarin Yellow R) Cl MordantOrange 6 Salicylate Azo (Chrome Orange GR) Cl Mordant Orange 10Salicylate Azo Cl Mordant Yellow 7 Salicylate Azo Cl Mordant Yellow 10Salicylate Azo Cl Mordant Yellow 12 Salicylate Azo Cl Mordant Green 31BON Acid Azo (Naphtho Chrome Green) Cl Azoic Coupling Component 2Arylamido N/A (Naphthol AS) RON acid Cl Azoic Coupling Component 45Arylamido N/A (Naphthol AS B1) BON acid 3-hydroxy-2-naphthoic acid (RONAcid) RON Acid N/A Xylidyl Blue 1 Aryl amido Azo BON acid

Dyes Based Upon Chromotropic Acid

[0033] Dyes based upon Chromotropic acid 8 are also substantive toalumina. Azo dyes are formed when chromotropic acid is reacted with adiazonium salt. Azo coupling occurs at positions 2 and/or 7.

Colorant Cl Acid Red 176 (Chromotrope 2B) Cl Acid Red 29 (Chromotrope2R) Plasmocorinth B Sulfonazo III(3,6-Bis(2-sulfophenylazo)-4,5-dihydroxy-2,7-naphthalene disulfonic acidsodium salt)2-(4-sulfophenylazo)-1,8-dihydroxy-3,6-naphthalenedisulfonic acid

Dyes Containing Acetoacetanilide

[0034] Dyes containing acetoacetanilide moieties 9 also contain thecorrect geometry to bond to alumina. Azo dyes couple to acetoacetanilidebeta to the two carboxyl groups. An example is CI Acid Yellow 99, 10.Acetoacetanilide will adsorb onto the surface of alumina.

Naphthoquinone Colorants

[0035] Naphthoquinone (11) type Structures are also useful for formingcomplexes with the surface of alumina:

[0036] CI Natural Black 1 (Hematoxylin) is another example of a dye thatcontains quinoid groups and is substantive to alumina.

Aluminum Dyes; Dyes Known to be Useful for Staining Anodized Aluminum

[0037] There are several dyes that are know to be useful for thecoloration of anodized aluminum, including CI Mordant Red 7 (EriochromeRed B), 12. It is believed that the geometry of the five memberedpyrazolone ring oxygen atom brings it into the correct position with thebeta-naphthol group for complexation with alumina. Thus, the followingstructure can be considered a functional equivalent to acarbonyl-hydroxy moiety. The structure also contains an iminalogousamide moiety, which is functionally equivalent to a vinalogous amide.

Aluminum Lake Forming Dyes

[0038] Certain anionic dyes may be precipitated using certain metal ionsto form an insoluble colored compounds know as Lake Pigments. Forexample, Erythrosine (Tetraiodofluorescein) forms an insoluble salt withaluminum ions. The salt is known as CI Pigment Red 172.

[0039] CI Pigment Blue 36 is the aluminum lake of indigo disulfonate(FD+C Blue 1):

[0040] In addition to a dye as described above, in some embodiments, itmay be desirable to bond other functional compounds or additives to thealumina. For instance, additives that assist in the dyeing process orthat stabilize the dye may also be bonded to the alumina if the additivecontains a moiety as described above. Such functional additives that maybe used include charge carriers, thermal oxidation stabilizers,crosslinking agents, plasticizers, a charge control additive, a flowcontrol additive, a filler, a surfactant, a chelating agent, a colorantstabilizer, or a combination thereof.

[0041] Various methods can be utilized to construct dye particles inaccordance with the present invention that contain a dye adsorbed ontoalumina. For instance, in some applications, the alumina and the dyecontaining a reactive moiety can be combined and reacted in an aqueoussolution.

[0042] In some embodiments, however, the dye may be difficult todissolve in water. In this embodiment, the dye can first be dissolved ina minimum quantity of a solvent. The solvent can be, for instance,acetone, ethanol or a similar liquid that is miscible with water. Afterthe dye is combined with the solvent, if desired, a surfactant can beadded in an amount greater than about 0% to about 50% by weight of dyesolids added. In general, the amount of surfactant added to the solventshould be minimized. One suitable surfactant that can be used, forinstance, is SURFYNOL 440 surfactant sold by Air Products and Chemicals,Inc. located in Allentown, Pa.

[0043] With rapid stirring, the dissolved dye solution can then be addedto a dilute aqueous suspension that contains particles comprisingalumina. Although not critical, better results may be achieved if theaqueous suspension is slightly heated.

[0044] After constant stirring for a sufficient amount of time, the dyedisperses by precipitation throughout the mixture and slowly dissolvesinto the water. Once dissolved into the water, the dye can be adsorbedby the alumina contained in the particles.

[0045] Once the dye is adsorbed onto the alumina, the resultingparticles can be used to formulate a suitable colorant composition foruse in various processes, such as in a suitable printing process.

[0046] The colorant composition may comprise an aqueous or non-aqueousmedium, although an aqueous medium is useful for applications whichemploy liquid printing mediums. The colorant compositions of the presentinvention contain particles, as well as, desirable colorant stabilizersand additives. For example, the colorant composition may contain theabove-described particles in combination with any of the followingadditives: a second colorant; a colorant stabilizer, such as a porphine;a molecular includant; a pre-polymer; and any additional components asdescribed above.

[0047] The present invention encompasses recording mediums such as inkjet inks comprising the nanoparticles disclosed herein. Inks used in inkjet printers are described in U.S. Pat. No. 5,681,380, assigned toKimberly-Clark Worldwide, Inc., which is incorporated herein byreference in its entirety. Ink jet inks will usually contain water asthe principal solvent, preferably deionized water in a range of betweenabout 20 to about 95 percent by weight, various co-solvents in an amountof between about 0.5 and about 20 percent by weight, and the particlesof the present invention.

[0048] Various co-solvents may also be included in the ink formulation.Examples of such co-solvents include a lactam such as N-methylpyrrolidone. However, other examples of optional co-solvents includeN-methylacetamide, N-methylmorpholine-N-oxide, N,N-dimethylacetamide,N-methyl formamide, propyleneglycolmonomethylether, tetramethylenesulfone, and tripropyleneglycolmonomethylether. Still other solventswhich may be used include propylene glycol and triethanolamine (TEA). Ifan acetamide-based cosolvent is also included in the formulation it istypically present at about 5 percent by weight, within a range ofbetween about 1.0-12 percent by weight.

[0049] Optionally, one or more humectants in an amount between about 0.5and 20 percent by weight may be included in the ink formula. Additionalhumectants for optional use in the formulation include, but are notlimited to, ethylene glycol, diethylene glycol, glycerine, andpolyethylene glycol 200, 400, and 600, propane 1,3 diol, other glycols,a propyleneglycolmonomethyl ether, such as Dowanol PM (Gallade ChemicalInc., Santa Ana, Calif.), polyhydric alcohols, or combinations thereof.

[0050] Other additives may also be included to improve ink performance,such as a chelating agent to sequester metal ions that could becomeinvolved in chemical reactions that could spoil the ink over time, forexample for use with metal complex dyes, a corrosion inhibitor to helpprotect metal components of the printer or ink delivery system, abiocide or biostat to control unwanted bacterial, fungal, or yeastgrowth in the ink, and a surfactant to adjust the ink surface tension.However, the use of a surfactant may be dependent on the type ofprinthead to be used. If a surfactant is included, it is typicallypresent in an amount of between about 0.1 to about 1.0 percent byweight. If a corrosion inhibitor is included, it is typically present inan amount between about 0.1 and about 1.0 percent by weight. If abiocide or biostat is included, it is typically present in an amountbetween about 0.1 and about 0.5 percent by weight.

[0051] If a biocide or biostat is added to the ink formulation, it maybe exemplified by Proxel GXL (Zeneca Corporation, Wilmington, Del.).Other examples include Bioban DXN (Angus Chemical Company, BuffaloGrove, Ill.). If a corrosion inhibitor is added to the formulation, itmay be exemplified by Cobratec (PMC Specialty Group Distributing ofCincinnati, Ohio). Alternate corrosion inhibitors include sodiumnitrite, triethanolamine phosphate, and n-acyl sarcosine. Still otherexamples include benzotriazole (Aldrich Chemical Company, Milwaukee,Wis.). If a surfactant is included in the formulation, it is typically anonionic surfactant exemplified by Surfynol 504 (Air Products andChemicals, Inc., Allentown, Pa.). Still other examples include Surfynol465, and Dynol 6.04 also available from Air Products. If a chelatingagent is included in the formulation it may be exemplified by anethylene diaminetetraacetic acid (EDTA). Other additives such as pHstabilizers/buffers, (such as citric acid and acetic acid as well asalkali metal salts derived therefrom), viscosity modifiers, anddefoaming agents such as Surfynol DF-65, may also be included in theformulation, depending on the product application.

[0052] Depending upon how the colorant composition is formulated, thecomposition can be used in various printing processes. For instance, inaddition to ink jet printing and other non-impact printers, the colorantcomposition can be used in screen printing processes, offsetlithographic processes, flexographic printing processes, rotogravureprinting processes, and the like. In some of the above printingprocesses, a thickener may need to be added to the colorant composition.The thickener can be, for instance, an alginate.

[0053] The recording medium or colorant composition of the presentinvention may be applied to any substrate to impart a color to thesubstrate. The substrate to which the composition is applied mayinclude, but is not limited to, paper, wood, a wood product orcomposite, woven fabrics, non-woven fabrics, textiles, films, plastics,glass, metal, human skin, animal skin, leather and the like. In oneaspect, the colorant composition or recording medium may be applied totextile articles such as clothing.

[0054] In one particular embodiment, a colorant composition containingparticles of the present invention may be applied to a substrate havinga negative surface charge. As described above, the alumina contained inthe particles of the present invention retain a positive charge evenafter adsorption of a dye. Consequently, the particles remain affixed tonegatively charged surfaces. In fact, wash durability of the colorantcomposition may occur if there is a substantial amount of chargedifference between the substrate and the particles of the presentinvention.

[0055] In view of the above, colorant compositions made according to thepresent invention are particularly well suited to being applied tonatural and synthetic substrates that have a negative surface charge.For instance, naturally occurring materials that generally contain anegative surface charge include cotton fibers, cellulose fibers, andsubstrates made therefrom. Such substrates include all types of fabrics,garments and apparel, paper products, and the like.

[0056] In addition to the above natural materials, in one particularembodiment, colorant compositions made according to the presentinvention have been found to be well suited to being applied tosubstrates made from synthetic polymers, such as thermoplastic polymers.Such substrates can include, for instance, woven and non-woven materialsmade from a polyolefin polymer such as polypropylene or polyethylene,polyester, and the like. In the past, various problems have beenexperienced in trying to affix dyes to these types of materials.Consequently, either complicated dye structures have been used or dyesand or pigments have been applied in conjunction with chemical binders.The particles of the present invention, however, can permanently affixto these materials without the use of chemical binders or complexchemical constructions.

[0057] Although not needed, in some embodiments it may be desirable topre-treat or post-treat the polymer substrates which may further serveto affix the dyes to the materials. For instance, substrates made fromsynthetic polymers can undergo a pretreatment process for increasing thenegative surface charge. For example, such pretreatment processesinclude subjecting the substrate to a corona treatment or to an electrettreatment. An electret treatment, for instance, is disclosed in U.S.Pat. No. 5,964,926 to Cohen, which is incorporated herein by referencein its entirety. Such pretreatments have been found not only to increasethe negative surface charge of polymeric materials, but also assist inwetting out the polymer and enhancing surface adhesion between thepolymer and the particles of the present invention.

[0058] In addition to pretreatment processes, substrates contacted withthe particles of the present invention can also undergo various posttreatment processes which further serve to affix the particles to thesubstrate. For example, in one embodiment, the treated substrate can besubjected to radio frequency radiation or to microwave radiation.Alumina is known to adsorb radio frequency radiation and microwaveradiation causing the particles to heat. Once heated, it is believedthat the particles become further embedded into the polymeric substrate.Further, the particles can be heated without also heating the substrateto higher than desired temperatures.

[0059] The present invention may be better understood with respect tothe following examples.

EXAMPLE 1

[0060] Aluminasol 200 (Nissan Chemical America) was diluted with DIwater to give a 2% Aluminasol 200 suspension. Meanwhile, carminic acid(0.02 g) was suspended in DI water (1 g). Carminic acid includeshydroxy-carbonyl moieties and can be represented as follows:

[0061] The zeta potential of alumina particles in the Aluminasol wasmonitored as carminic acid was dripped into the measurement cell. Thezeta potential did not change as more carminic acid was added. Asignificant color shift was observed as the carminic acid (red/orange)was added to the Aluminasol (bluish magenta). The following zetapotential results were obtained: Zeta Potential 2% Aluminasol 56.70 mVAluminasol + 2 Drops Carminic 49.27 mV Aluminasol + 5 drops carminic56.68 mV Aluminasol + 7 drops carminic 58.59 mV

[0062] As shown above, the positively charged alumina was capable ofadsorbing carminic acid without going through a charge reversal step.

EXAMPLE 2

[0063] Aluminasol 200 (Nissan Chemical America, 2 g) was diluted with DIwater (98 g) with good stirring. Carminic acid (Aldrich, #22,925-3)(0.5011 g) was suspended in DI water (23.7135 g) with good stirring. Thecarminic acid did not dissolve completely at this concentration, and sowhenever portions were taken, they were taken while stirring vigorouslyso that suspended solids were also withdrawn. A hypodermic syringe wasused to withdraw 1 ml of carminic acid suspension. This was added to thediluted Aluminasol 200 with good stirring. The suspension changed from awhite to a bluish red.

[0064] The Zeta potential was monitored after addition to check forchanges as follows: Zeta Potential Initial (2% Aluminasol) +55.70 mV 2min after carminic acid addition +45.08 mV 5 min after carminic acidaddition +45.68 mV

[0065] This mixture was allowed to stir overnight. The next morning, alldye had dissolved, and no dye crystals were observed.

EXAMPLE 3

[0066] In this example, in addition to carminic acid, CI Acid Blue 25and CI Acid Blue 45 were bonded to alumina in accordance with thepresent invention. CI Acid Blue 25 and CI Acid Blue 45 have thefollowing structures:

[0067] 0.2008 g CI Acid Blue 25 (Aldrich) was added to 19.7735 g DIwater and stirred to give a suspension, which was stirred for 30minutes. 1 ml of this was added to a mixture containing 2 g Aluminasoland 98 g DI water. Mixture stirred overnight to ensure that all dye haddissolved.

[0068] 0.2507 g of CI Acid Blue 45 (Aldrich) was suspended in 20.1751 gDI water with stirring for 30 minutes. 1 ml (syringe) was added to amixture of 2 g Aluminasol and 98 g of DI water to give a blue complex.Mixture stirred overnight to ensure that all dye dissolved.

[0069] In the following sample, a high concentration of Aluminasol 200was combined with carminic acid. Specifically, 0.111 g glacial aceticacid (Fischer, ACS plus reagent grade) was diluted with 29.795 g DIwater. This was added to 49.941 g of Aluminasol 200, slowly with goodstirring. This mixture was stirred for 20 mins, at which point, 4 ml(measured using a syringe) of a suspension of carminic acid in DI water(0.5011 g carminic acid in 23.7135 g water) was added at once, with goodstirring. Mixture stirred overnight.

[0070] A fourth sample was then constructed containing the sameingredients (carminic acid) in the same amounts as listed in Example 2above.

[0071] All mixtures appeared to be homogeneous in that upon standing forthree hours, no sludge settled out, and no dark dye crystals wereobserved. Zeta potentials and particle size analysis were conductedusing a Brookhaven Instrument PALS Zeta potential analyzer for all thesamples except the sample containing CI Acid Blue 25. The followingresults were obtained: Half Zeta Mean Distribution System PotentialDiameter Width  2% Aluminasol/Acid Blue 45 +40.69 mV 333.5 nm  94.7 nm 2% Aluminasol/Carminic Acid +45.14 mV 300.6 nm 139.5 nm 50%Aluminasol/Carminic Acid +43.73 mV 347.3 nm 181.6 nm

[0072] The above three solutions were then subjected to a dialysis testto demonstrate that the dye was adsorbed onto the alumina surfaces.Specifically, the three solutions were dialyzed against 3% glacialacetic acid using Sigma Dialysis Tubing (Cellulose, 12,000 mw cut off,Sigma D-0655. Tubing was soaked in DI water for two hours prior to useto remove glycerine, and to make the tubing flexible.) As a control, asmall amount of carminic acid was added to a dialysis tubing and placedin a bath containing 3% acetic acid. Within 2 hours, carminic acid hadtraversed the cellulose membrane and had colored the 3% acetic acidsolution. No color was observed from the aluminasol mixtures,suggesting, along with the color change, that the colorant was stronglysorbed by the particles. The next morning, the 50% aluminasol/carminicacid solution had colored the water bluish red. However, it is believedthat the bag had ruptured. Also, a very faint, almost indiscernible bluecoloration was noticed in the dialysis solution of the aluminasol acidblue 45 dialysis, suggesting that this colorant did not as stronglyadsorb into the alumina.

EXAMPLE 4

[0073] The following tests were conducted to demonstrate thewashfastness of the particles of the present invention on cotton.

[0074] The three compositions prepared in Example 3 above containing 2%aluminasol/Acid Blue 45; 2% aluminasol/carminic acid, and 50%aluminasol/carminic acid were spotted onto cotton poplin fabric (0.01198 g/cm², from Yuhan-Kimberly, uncoated) and dried overnight at 60° C.As the aluminasol containing mixtures were dropped onto the cotton, itwas observed that only the flooded area of the fabric took up color.Colorless water wicked out from around the spotted area suggesting thati) no unadsorbed dye was present in the mixture, and ii) thenanoparticles sorbed onto the cotton, and were immobilized.

[0075] A control sample was also prepared. In particular, a carminicacid solution was first formulated containing 0.5011 grams of carminicacid in 23.7135 grams of DI water. The carminic acid solution wasdropped onto cotton poplin fabric using a pipette and allowed to dryovernight at 60° C.

[0076] Samples were washed by i) rinsing under a hot running tap, andthen by stirring for 2 hours in 2 liters of water containing 1 g/literAerosol OT (dioctyl sodium sulfosuccinate surfactant obtained from CytecIndustries of West Patterson, N.J.) and 1 g/liter of sodium bicarbonate,with stirring (mechanical paddle stirrer). Samples were entered into thewashing bath at 60° C., and the bath cooled over two hours to 30° C. Thefabric was rinsed in cold water, then dried in the air at ambient.

[0077] The Carminic acid of the control sample rinsed out of the cotton.Almost all of the dye/Aluminasol complex remained as a bluish-red stain.

EXAMPLE 5

[0078] The following tests were conducted to demonstrate thewashfastness of particles made according to the present invention on apolypropylene non-woven spunbond fabric. The spunbond fabric tested hada basis weight of 2 osy.

[0079] Polypropylene spunbond was smeared with i) carminic acid, ii) theconcentrated 50% Aluminasol/carminic acid complex suspension prepared inExample 3 and iii) the 2% Aluminasol/carminic acid complex suspensionprepared in Example 3. In all cases, the polypropylene was difficult towet out with these materials, and so smearing was required using arubber-gloved finger and the teat pipette used to apply the liquids.Once the material had been smeared on forcibly, the material showedlittle retraction. The samples were allowed to dry overnight at 60° C.

[0080] More polypropylene was smeared with the 50% Aluminasol/carminicacid complex. These samples were dried at 60° C. and then cut in half.Half of the samples were subjected to microwave radiation (Sharpcarousel domestic microwave oven, model #R-410 CK, output 1100 Watt) fora range of times. (10 seconds, 20 seconds, 28 seconds)

[0081] All polypropylene samples were washed using the same procedure asfor the cotton in Example 4 above. The following results were obtained:

[0082] i) Carminic acid of the control sample rinsed out of the PP.

[0083] ii) Some, but not all of the aluminasol/carminic acid inks wereretained on the polypropylene. The nature of the washing out was not ageneral fading of the area. However, there appeared to be a loss of allmaterial from certain areas, but not others. In other words, it lookedas though the ink had not wet out the polypropylene.

[0084] iii) Considerably more aluminasol/carminic acid was retained onsamples that were microwaved prior to washing. It is thought that themicrowave treatment may have heated the colored particles, allowing themto embed in the polypropylene. Microwaving for longer time did notconsiderably improve the washfastness of the prints.

EXAMPLE 6

[0085] In this example, instead of using an alumina sol, a solcontaining silica particles that had an alumina surface coating wereused. The surface coated silica suspension was obtained from NissanChemical America of Houston, Tex. The suspension is sold under the tradename SNOWTEX-AK.

[0086] 50 ml of 20% wt/wt suspension of SNOWTEX-AK (Nissan ChemicalAmerica, Houston, Tex.) was stirred at ambient temperature while 0.2grams of carminic acid dye (Aldrich Chemical Company, Milwaukee, Wis.)was added. Stirring was continued overnight and resulted in a dramaticcolor change from blood red to blue/purple.

[0087] The physical parameters of the nanoparticles are: SNOWTEX-AKSize: 62 nm and Zeta Potential: +36 mV. SNOWTEX-AK Size: 83 nm and ZetaPotential: +35 mV. with carminic acid

[0088] The bond formation of the aluminum-dye complex did not result ina change in zeta potential.

[0089] The above “ink” solution was applied to 4″×4″ pieces of untreatedcotton fabric and allowed to air-dry. A similar control sample wasconstructed using only carminic acid. The dried fabrics were thensubjected to a washing cycle in 2 litres of water containing Ajax liquiddetergent and sodium bicarbonate at 60° C. for 2 hours. The fabricsamples were then air-dried. The SNOWTEX-AK/carminic acid sample did notloose any color after the washing cycle. In contrast, the control sample(a sample stained with 0.2 g Carminic Acid in 50 ml water, dried underthe same conditions) lost all of the color upon washing under the sameconditions.

EXAMPLE 7

[0090] The following example demonstrates the application of the presentinvention to other functional compounds as opposed to dyes.

[0091] Tetracycline is an antibacterial agent that contains acarbonyl-hydroxy function capable of bonding with alumina in accordancewith the present invention. Tetracycline is a series of isomers ofcyclomycin. Tetracycline contains as a principle component thefollowing:

[0092]4S-(4,4,5,6,12)-4-(dimethylamino)-1,4,4,5,5,6,11,12-octahydro-3,6,10,12,12-pentahydroxy-6-methyl-1,11-dioxo-2-naphthacenecarboxamide.

[0093] The UV-visible absorbance spectrum of Tetracycline was measuredusing a UV-visible spectrophotometer (Perkin-Elmer UV-Visiblespectrophotometer.) Tetracycline was found to absorb at 357 nm in water.When SNOWTEX AK suspension (as described in Example 6) was added to thetetracycline solution, a bathochromic shift occurred to give anabsorbance of 365 nm, suggesting that the tetracycline had adsorbed ontothe alumina surface of SNOWTEX AK particles.

[0094] These and other modifications and variations to the presentinvention may be practiced by those of ordinary skill in the art,without departing from the spirit and scope of the present invention,which is more particularly set forth in the appended claims. Inaddition, it should be understood that aspects of the variousembodiments may be interchanged both in whole or in part. Furthermore,those of ordinary skill in the art will appreciate that the foregoingdescription is by way of example only, and is not intended to limit theinvention so further described in such appended claims.

What is claimed:
 1. A composition of matter comprising: a particlecontaining alumina, at least a portion of the alumina being present on asurface of the particle; and a functional compound bonded to the aluminaon the surface of the particle, the functional compound prior to bondingwith the alumina containing a moiety comprising:

or a tautomer thereof, or a functional equivalent thereof and wherein Rand R′ comprise independently hydrogen, an alkyl group, or an arylgroup.
 2. A composition as defined in claim 1, wherein the particlescontaining alumina bonded to the functional compound are positivelycharged.
 3. A composition as defined in claim 1, wherein the particleconsists essentially of alumina.
 4. A composition as defined in claim 1,wherein the particle comprises a core material coated with alumina.
 5. Acomposition as defined in claim 4, wherein the core material comprisessilica.
 6. A composition as defined in claim 1, wherein the functionalcompound comprises a UV absorber, a pharmaceutical, an odor controlagent, a fragrance, a therapeutic agent, a nutriceutical agent, ananti-bacterial agent, an anti-microbial agent, an anti-viral agent, or axenobiotic.
 7. A composition as defined in claim 1, wherein the particlecontaining alumina bonded to the functional compound has an averagedimension of less than about 1 mm.
 8. A composition as defined in claim1, wherein the particle containing alumina bonded to the functionalcompound has an average dimension of less than about 100 microns.
 9. Acomposition as defined in claim 1, wherein the particle containingalumina bonded to the functional compound has an average dimension ofless than about 1,000 nm.
 10. A composition as defined in claim 1,wherein the functional compound comprises hydrocortisone.
 11. Acomposition as defined in claim 1, wherein the functional compoundcomprises ascorbic acid.
 12. A composition as defined in claim 1,wherein the functional compound comprises aspartame.
 13. A compositionas defined in claim 1, wherein the functional compound comprises acyclomycin.
 14. A composition as defined in claim 1, wherein thefunctional compound comprises tetracycline.
 15. A composition as definedin claim 1, wherein the particles are amorphous.
 16. A composition asdefined in claim 1, wherein the particle containing alumina bonded tothe functional compound has a zeta potential of at least 20 mV.
 17. Acomposition as defined in claim 1, wherein at least two functionalcompounds are bonded to the alumina.
 18. A composition as defined inclaim 1, wherein the functional compound comprises a colorant.
 19. Acomposition as defined in claim 1, wherein the composition comprises aplurality of the particles containing alumina bonded to the functionalcompound contained in a liquid vehicle.
 20. A nanoparticle for aprinting process comprising: a particle containing alumina, at least aportion of the alumina being present on a surface of the particle; and acolorant compound bonded to the alumina on the surface of the particle,the colorant compound prior to bonding with the alumina containing amoiety comprising:

or a tautomer thereof, or a functional equivalent thereof and wherein Rand R′ comprise independently hydrogen, an alkyl group, and aryl group.21. A nanoparticle as defined in claim 20, wherein the particlescontaining alumina bonded to the colorant compound are positivelycharged.
 22. A nanoparticle as defined in claim 20, wherein the particleconsists essentially of alumina.
 23. A nanoparticle as defined in claim20, wherein the particle comprises a core material coated with alumina.24. A nanoparticle as defined in claim 23, wherein the core materialcomprises silica.
 25. A nanoparticle as defined in claim 20, wherein thenanoparticle has an average dimension of less than about 1,000 nm.
 26. Ananoparticle as defined in claim 20, wherein the nanoparticle has anaverage dimension of less than about 500 nm.
 27. A nanoparticle asdefined in claim 20, wherein the particle containing alumina bonded tothe colorant compound has a zeta potential of at least 20 mV.
 28. Ananoparticle as defined in claim 20, wherein the alumina and thecolorant compound both have a positive zeta potential.
 29. Ananoparticle as defined in claim 20, wherein the alumina on the surfaceof the particle is further bonded to a functional additive.
 30. Ananoparticle as defined in claim 29, wherein the functional additivecomprises a charge carrier, a thermal oxidation stabilizer, aviscoelastic property modifier, a cross-linking agent, a plasticizer, acharge control additive, a flow control additive, a filler, asurfactant, a chelating agent, a leuco dye, and colorant stabilizer, ora combination thereof.
 31. A nanoparticle as defined in claim 20,wherein the colorant compound comprises a dye.
 32. A nanoparticle asdefined in claim 31, wherein the dye contains an anthraquinonechromophore.
 33. A nanoparticle as defined in claim 31, wherein the dyecontains salicylate or 3-hydroxy-2-naphthoic acid moieties.
 34. Ananoparticle as defined in claim 31, wherein the dye is based onchromotropic acid.
 35. A nanoparticle as defined in claim 31, whereinthe dye contains acetoacetanilide.
 36. A nanoparticle as defined inclaim 31, wherein the dye contains a naphthoquinone.
 37. A nanoparticleas defined in claim 31, wherein the dye comprises a mordant dye.
 38. Ananoparticle as defined in claim 31, wherein the dye comprises CIMordant Red 7 or Eriochrome Red B.
 39. A recording medium comprising: aplurality of particles containing alumina, at least a portion of thealumina being present on a surface of the particles; a colorant compoundbonded to the alumina on the surface of the particle, the functionalcompound prior to bonding with the alumina containing a moietycomprising:

or a tautomer thereof, or a functional equivalent thereof and wherein Rand R′ comprise independently hydrogren, an alkyl group, or an arylgroup; and a liquid vehicle.
 40. A recording medium as defined in claim39, wherein the colorant compound contained the moiety:

or a tautomer.
 41. A recording medium as defined in claim 39, whereinthe colorant compound contained the moiety:

and wherein R and R′ are hydrogen.
 42. A recording medium as defined inclaim 39, wherein the colorant compound contained the moiety:

or a tautomer.
 43. A recording medium as defined in claim 39, whereinthe particles consist essentially of alumina.
 44. A recording medium asdefined in claim 39, wherein the particles comprise a core materialcoated with an alumina.
 45. A recording medium as defined in claim 44,wherein the core material comprises silica.
 46. A recording medium asdefined in claim 39, wherein the particles have an average dimension ofless than about 1,000 nm.
 47. A recording medium as defined in claim 39,wherein the particles containing the alumina bonded to the colorantcompound has a zeta potential of greater than about 20 mV.
 48. Arecording medium as defined in claim 39, wherein the alumina and thecolorant compound together have a positive zeta potential.
 49. Arecording medium as defined in claim 39, wherein the colorant compoundcomprises a dye.
 50. A recording medium as defined in claim 49, whereinthe dye contains an anthraquinone chromophore.
 51. A recording medium asdefined in claim 49, wherein the dye contains salicylate or3-hydroxy-2-naphthoic acid moieties.
 52. A recording medium as definedin claim 49, wherein the dye is based on chromotropic acid.
 53. Arecording medium as defined in claim 49, wherein the dye containsacetoacetanilide.
 54. A recording medium as defined in claim 49, whereinthe dye contains a mordant dye.
 55. A recording medium as defined inclaim 49, wherein the dye is CI Mordant Red
 7. 56. A recording medium asdefined in claim 49, wherein the dye contains a naphthoquinone.
 57. Aprinting process comprising ejecting the recording medium of claim 39 inthe form droplets from an orifice in according with a recording signalto form an image on a substrate.
 58. The printing process of claim 57,wherein the substrate comprises a woven fabric, a non-woven fabric, apolymeric film, glass, or a paper.
 59. The printing process of claim 57,wherein the process is an ink-jetting process.
 60. An article ofmanufacture comprising: a substrate having a receiving surfacecontaining negative charges; and a plurality of positively chargedparticles bonded to the receiving surface of the substrate throughcoulombic attraction, the particles containing alumina, at least aportion of the alumina being present on a surface of the particles, andwherein a functional compound is bonded to the alumina on the surface ofthe particle, the functional compound prior to bonding with the aluminacontaining a moiety comprising:

or a tautomer thereof, or a functional equivalent thereof and wherein Rand R′ comprise independently hydrogen, an alkyl group, or an arylgroup.
 61. An article as defined in claim 60, wherein the particlecomprises a core material coated with alumina.
 62. An article as definedin claim 60, wherein the core material comprises silica.
 63. An articleas defined in claim 60, wherein the functional material comprises acolorant, a UV absorber, a pharmaceutical, an odor control agent, afragrance, a therapeutic agent, a nutriceutical agent, an anti-bacterialagent, an anti-microbial agent, an anti-viral agent, or a xenobiotic.64. An article as defined in claim 60, wherein the particle containingalumina bonded to the functional compound has an average dimension ofless than about 1 mm.
 65. An article as defined in claim 60, wherein theparticle containing alumina bonded to the functional compound has anaverage dimension of less than about 1,000 nm.
 66. An article as definedin claim 60, wherein the functional compound comprises hydrocortisone,ascorbic acid, or aspartame.
 67. An article as defined in claim 60,wherein the functional compound comprises tetracycline.
 68. An articleas defined in claim 60, wherein the particle containing alumina bondedto the functional compound has a zeta potential of at least 20 mV. 69.An article as defined in claim 60, wherein the plurality of particlesare contained within a liquid vehicle when applied to the substrate. 70.An article as defined in claim 60, wherein the functional compoundcomprises a dye.
 71. An article as defined in claim 70, wherein thesubstrate comprises a woven or non-woven material comprising syntheticpolymeric fibers.
 72. An article as defined in claim 71, wherein thesubstrate is subjected to a corona treatment prior to bonding with theplurality of positively charges particles.
 73. An article as defined inclaim 71, wherein the substrate is subjected to an electret treatmentprior to bonding with the plurality of positively charges particles. 74.An article as defined in claim 71, wherein the article has been exposedto microwave radiation or radio frequency radiation after the substrateand the plurality of charged particles have been bonded together.
 75. Anarticle as defined in claim 70, wherein the substrate comprises naturalfibers carrying the negative charges.
 76. An article as defined in claim75, wherein the natural fibers comprise cotton or cellulose fibers. 77.An article as defined in claim 70, wherein the dye contains ananthraquinone chromophore.
 78. An article as defined in claim 70,wherein the dye contains salicylate or 3-hydroxy-2-naphthoic acidmoieties.
 79. An article as defined in claim 70, wherein the dye isbased on chromotropic acid.
 80. An article as defined in claim 70,wherein the dye contains acetoacetanilide.
 81. An article as defined inclaim 70, wherein the dye contains a naphthoquinone.
 82. An article asdefined in claim 70, wherein the colorant compound contained the moiety:

or a tautomer of this moiety.
 83. An article as defined in claim 70,wherein the colorant compound contained the moiety:

and wherein R and R′ are hydrogen.
 84. An article as defined in claim70, wherein the colorant compound contained the moiety:

or a tautomer of this moiety.
 85. An article as defined in claim 70,wherein the plurality of particles have an average dimension of lessthan about 1,000 nm.
 86. An article as defined in claim 60, wherein thereceiving surface of the substrate and the particles have a surfacecharge difference of at least 42 mV.
 87. An article as defined in claim70, wherein the receiving surface of the substrate and the particleshave a surface charge difference of at least 42 mV.
 88. A method ofmaking a composition of matter comprising: providing a plurality ofparticles, the particles containing alumina, at least a portion of thealumina being present on a surface of the particles; and bonding to thealumina on the surface of the particles a functional compound, thefunctional compound prior to bonding with the alumina containing amoiety comprising:

or a tautomer thereof, or a functional equivalent thereof and wherein Rand R′ comprise independently hydrogren, an alkyl group, or an arylgroup; and
 89. A method as defined in claim 88, wherein the particleconsists essentially of alumina.
 90. A method as defined in claim 88,wherein the particles comprise a core material coated with an alumina.91. A method as defined in claim 90, wherein the core material comprisessilica.
 92. A method as defined in claim 88, wherein the functionalmaterial comprises a colorant, a UV absorber, a pharmaceutical, an odorcontrol agent, a fragrance, a therapeutic agent, a nutriceutical agent,an anti-bacterial agent, an anti-microbial agent, an anti-viral agent,or a xenobiotic.
 93. A method as defined in claim 88, wherein theparticle containing alumina bonded to the functional compound has anaverage dimension of less than about 1 mm.
 94. A method as defined inclaim 88, wherein the particle containing alumina bonded to thefunctional compound has an average dimension of less than about 1,000nm.
 95. A method as defined in claim 89, wherein the functional compoundcomprises hydrocortisone, ascorbic acid, or aspartame.
 96. A method asdefined in claim 88, wherein the functional compound comprisestetracycline.
 97. A method as defined in claim 88, wherein the particlesare amorphous.
 98. A method as defined in claim 88, wherein the particlecontaining alumina bonded to the functional compound has a zetapotential of at least 20 mV.
 99. A method as defined in claim 88,wherein at least two functional compounds are bonded to the alumina.100. A method as defined in claim 88, further comprising the step ofcombining the particles bonded with the functional compound with aliquid vehicle.
 101. A method as defined in claim 100, wherein thecomposition comprises an ink composition.
 102. A method as defined inclaim 88, wherein the functional compound comprises a dye.
 103. A methodas defined in claim 102, wherein the dye contains an anthraquinonechromophore.
 104. A method as defined in claim 102, wherein the dyecontains salicylate or 3-hydroxy-2-naphthoic acid moieties.
 105. Amethod as defined in claim 102, wherein the dye is based on chromotropicacid.
 106. A method as defined in claim 102, wherein the dye containsacetoacetanilide.
 107. A method as defined in claim 102, wherein the dyecontains a naphthoquinone.